The overall goal of this Phase I STTR proposal from the University of Washington (UW) and Vical Incorporated is to advance a multivalent, plasmid DNA (pDNA) immunotherapeutic vaccine for HSV-2 through preclinical development up to point of a pre-IND meeting. This proposal will combine the expertise of the UW group, the leading HSV-2 research group in the world, and the capabilities at Vical, one of the largest manufacturers of clinical plasmid DNA (pDNA). The formulated vaccine would contain up to five HSV-2 viral genes that are known to induce CD4+ and cytotoxic CD8+ T cell responses in man. The vaccine would be designed to decrease the shedding of HSV-2 virus, which would be evaluated in the clinical phase by quantitative daily genital shedding measures as a surrogate marker of clinical benefit. An observed decrease in viral burden would be followed by definitive trials that examined the clinical recurrence rate in the vaccine and then the effect on transmission of the disease. This STTR proposal will support our HSV immunotherapeutic vaccine development through: 1) identification of the genes to be included in the vaccine; 2) the design of the specific sequences of those genes; 3) the cloning into a clinical plasmid backbone and evaluation of expression in vitro using novel assay methodology; 4) testing immunogenicity of the individual plasmids; and 5) evaluation of various combinations in vivo. Once the vaccine composition is determined, we will hold a pre-IND meeting to determine the pre-clinical toxicology and safety studies that will be needed. The specific milestone to be reached for moving to Phase II funding by the STTR program will be to have a successful pre-IND meeting that defines the developmental pathway forward into human Phase 1 safety and Phase 2 proof-of principal clinical trials.